You have one lane per core in the system.
So a system with 4 CPUs, each with one core would be a 4-lane highway (as stated in the article) - or you can think of it as 4 single lane highways.
If you have a single quad-core then you have a 4-lane highway.

If you have 4 quad-core CPUs, then you have 4 4-land highways (or a single 16-lane highway).

I'd like to mention here that the timeslices of each task are NOT 10 ms, but 100 ms as an average (nice val 0) & goes down to 10 ms (assuming HZ=100) for nice val -19.
This is ofcourse for the pre-CFS days, which is when I believe the article was written